For the most part OpenOffice.org does what an office suite needs to do and thus far it has served me well. Recently however, I came across two features that affected me as an average user of spreadsheet applications.
Firstly, I wanted to draw a chart of data that wasn’t located in contiguous regions of the spreadsheet. That is, the cells weren’t next to one another. Step one: Create a blank chart. Step two: Right click in the chart and select “Data Ranges.” So far, Excel and Calc work exactly the same.

OpenOffice.org Calc Data Range selection dialog for charts